I'm not trying to discount "heat seeking projectiles", i'm trying to discount "heat seeking projectiles that level everything within a proximity".

I have no problem with kunais that follow ninjas around. We've already seen needles that did it, sound waves that did it, sand that did it.....
Besides, the whole discussion is about technology vs jutsu, not jutsu simulating technology.

Xanbcoo: If you are going to refer to "missiles" as projectiles, then his needles werent LIKE missiles, they WERE missiles. To say "like" is to make a comparison to something that it's similiar to but ISN'T.